More than 90 per cent of the world rice is grown and consumed in Asia, where about 80 per cent of the world’s people live. In Pakistan, rice is the second main food crop after wheat and a foreign exchange earner cash crop. Punjab is the biggest rice producer followed by Sindh, Balochistan and the NWFP. In Upper Sindh, rice is grown over 1.2 million acres in districts Larkana, Shikarpur and Jacobabad. Besides, its illegal cultivation is undertaken in cotton-growing districts on millions of acres.
However, this year the area under illegal paddy is the lowest (within 100,000 acres) in the upper Sindh. Rice variety IRI-6 is the main variety covering over 80 per cent of the total paddy cultivation. The other varieties comprise DR-83, Russi, Sadagulab, Sarsar, Shaheen, Firdausi and some locals. The phenomenon of short-fall of rains, to some extent, has proved a blessing in disguise following lowering of under-ground water table. In chronic waterlogged areas, reclamation of marginal land becomes possible. In slightly waterlogged areas, lowering of water table has rendered millions of acres fit for cotton crop, particularly in districts Ghotki, Sukkur and Khairpur. However, on the whole, water shortage, which was about 40 per cent as per official estimate during Rabi season, affected wheat, banana, sugarcane and other crops in Sindh province.
In the beginning of April this year, due to water shortfall at Tarbela, water-table in the Indus River receded fast. Water discharge in the Sukkur Barrage came down from 18600 cusecs to 16400 cusecs resulting closure of BS Feeder, Desert Pat Feeder, Ghotki Feeder, Kirthar and Rice canals. These canals were closed for a month to carry out water rotation programme in the barrage area. Extent of water shortage during early kharif season in Sindh could be gauged from the fact that the Sindh government was directed to convert its perennial canals into non-perennial ones and impose restriction on rice cultivation in certain areas of the province to cope with the water crisis. However, following improvement in the availability of water in the River Indus, rice-growing areas of Upper Sindh received water from July.
Accordingly, transplanting of paddy started with the rice seedling raised with tube well water. But majority of growers had no rice seedling for transplanting. Thus, transplantation of paddy crop in general was taken with the nursery raised with canal water. As a result of this, 80 to 85 per cent rice crop in upper Sindh was sown late.
In view of the fact that late sown rice crop harbour more pests, a survey of standing crop was undertaken during the last week of September covering area of districts Larkana, Jacobabad and Shikarpur and it was found, unexpectedly of course, that there was no emergence of stem borer’s moth as yet, in general. However, the reasons of such a phenomenon warrants a proper study.
WHITE-BACKED PLANT HOPPER (WBPH):Early sown DR-83 which are in the process of harvesting and early sown IRI-6 rice variety which has attained grain formation stage have escaped WBPH infestation. However, majority of the standing rice crop which is in its tillering-to-heading stage, harbour WBPH population. Population above ETL are mostly in the field which are either under shade of trees or highly fertilized with urea (nitrogen fertilizer).
White-backed plant hopper is light brown in colour with a white whitish stripe on its back. The nymphs and adults suck cell-sap from the leaf surface. The leaves of attacked plant turn yellow and later on rust red. The attacked plants ultimately dry up without producing ears in early stage and grains in latter stage attack.
CONTROL MEASURES: Except for a few progressive growers who have sprayed entire crops for WBPH control, general growers are not aware of this tiny menace yet. As a matter of fact, damage of the pest become visible only when patchy circular hopper burns start showing following severe infestation, which stage has not arrived as yet. Many growers are seen applying granular pesticides on paddy crop, but the application of pesticide is not aimed at WBPH rather as a prophylactic treatment against stem borer.
According to growers who are almost ignorant, WBPH comes in October or early November. The irony of the fact is that almost 40 per cent rice crop in the upper Sindh is still in its initiation stage which harbour WBPH population but the majority of growers are unaware of the menace.
SUGGESTIONS: The Provincial Agriculture (Extension) Department using its field force, print and electronic media should persuade growers to undertake necessary control measures against the WBPH infestation. Since paddy area in upper Sindh comprises many fish ponds pesticides having high fish toxicity should be avoided. Standing rice crop grown illegally in the cotton belt has also been found under WBPH attack. Accordingly growers of cotton belt should also be advised to start control measures against the very pest without any delay.